1. Field of the Invention
The present invention relates to the field of firearms. More particularly, the invention pertains to apparatus and method for firing a firearm which ensures that the entire back flash is directed away from the user's face.
2. Description of the Prior Art
Firearms, particularly muzzle-loading type firearms are old and well known. The typical firearm includes a receiver, a barrel extending forward from the receiver and a trigger mechanism mounted to the receiver including a hammer mounted proximate the rear end of the receiver. The barrel has a bore therethrough and a chamber formed at the rear end thereof. In a pistol type of firearm a handle will generally be provided, extending downward from the receiver. In a rifle type of firearm generally a stock is provided extending rearward from the receiver.
One class of firearms known as muzzle-loader is characterized by the method of loading where a propellant charge and a projectile are each individually loaded through the bore and into the chamber of the barrel. In this class of firearms a separate source of ignition is provided for igniting the charge. Such a source of ignition may be as simple as a flint, or it may be an ignition cap which contains an ignitable substance, for example potassium chlorate, which ignites when struck by the hammer.
It is known to use a nipple to direct the ignition spark toward the charge. The nipple may have a seat for mounting the ignition cap thereto. An input port is located at the rearward end of the nipple, an output port is located at the forward end of the nipple. Generally, the output port has a smaller cross-sectional area than the input port.
On ignition of the propellant charge there is a rapid and large increase in pressure within the chamber. The large increase in pressure causes the projectile to be propelled down the length of the bore and out the barrel at a high velocity. At the same time, some of the hot gases and debris from the ignition is directed backward due to the inertia of the projectile. This backward directed component of the ignition process is termed back flash. Temperatures exceeding eight hundred degrees Fahrenheit, pressures between two thousand and eighteen thousand pounds per square inch and speeds of between five hundred and sixty and two thousand feet per second are typical characteristics associated with the back flash. The back flash presents a substantial risk of danger to the shooter. The back flash follows the path of least resistance, most often being back through the nipple. Traditionally, the outlet port of the nipple is located relatively close to the shooter's eyes, especially the shooter's sighting eye. The back flash and the accompanying hot gases can easily bum the shooter's eyes and face. It can also cause the ignition cap to fragment, the fragments presenting a grave risk of injury to the eyes and face of the shooter. At the very least the back flash presents a substantial annoyance to the shooter and a distinct probability of injury. As a consequence, much effort has been directed at minimizing and redirecting the back flash in an effort to make muzzle-loading guns safer.
Several attempts have been made to overcome the back flash problem. Some have tried to redirect the back flash. U.S. Pat. Nos. 5,109,622 issued to Echeberria and 4,715,139 to Rodney disclose the use of a downward directed port, proximate the inlet port of the nipple for releasing the back flash. U.S. Pat. No. 4,700,499 issued to Knight discloses a lateral port, proximate the outlet port of the nipple for releasing the back flash.
A further attempt at redirecting the back flash is shown in U.S. Pat. No. 4,888,901 issued to French. The French reference discloses the placement of a pair of lateral exhaust ports between the outlet of the nipple and a flash plate or breech plug. Examination and testing of the French design has revealed that significant dangers are still presented to the shooter. The location of the exhaust ports is still unacceptably close to the shooter's face, and presents a particular risk when the firearm is being discharged into a breeze. Also, a significant amount of backflash still escapes through the nipple where it exhausts proximate the shooter's face and eyes. A further problem arises from leakage of backflash between the receiver and the outside surface of the nipple.
These efforts have failed for several reasons. The attempts at redirecting back flash have not reduced the magnitude of the problem, rather they have simply moved the problem from one location on the firearm to another. All of the above cited efforts expel the back flash directly to the atmosphere. These attempted solutions still permit the back flash to follow a path through the nipple which causes the ignition passageway of the nipple to become clogged with debris such as carbon which requires increased time and effort to be spent in cleaning the firearm. It also leads to excessive cap fragmentation which can cause damage to the moving parts of the firearm in addition to the shooter. All of these attempted solutions continue to present a grave risk of injury to the shooter.
There is a demonstrated need in the field of firearm technology for a device which overcomes the aforementioned problems and provides a safe muzzle-loaded firearm in which the back flash is dissipated to some significant degree before it is exhausted and is exhausted away from the ignition cap and the shooter.